Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value. You may repeat this process any number of times.
{0}
Dark Sphere
Artifact
{T}, Sacrifice Dark Sphere: The next time a source of your choice would deal damage to you this turn, prevent half that damage, rounded down.
{1}{B}
Sickening Dreams
Sorcery
As an additional cost to cast this spell, discard X cards.
Sickening Dreams deals X damage to each creature and each player.
{3}{B}{B}
Sidisi, Undead Vizier
Legendary Creature - Zombie Naga
Deathtouch
Exploit (When this creature enters the battlefield, you may sacrifice a creature.)
When Sidisi, Undead Vizier exploits a creature, you may search your library for a card, put it into your hand, then shuffle.